Electron switch control system



Sept. 29, 1953 T. H. CLARK ELECTRON SWITCH CONTROL SYS EM 2 Sheets-Sheet 1 Filed April 50, 1947 TELEPHONE D/A L FIGZ.

INVENTOR. TREVOR HAZARD CLARK BY WP 25 I ,4 7-

ATTORNEY Sept. 29, 1953 T. H. CLARK ELECTRON SWiTCH CONTROL SYSTEM 2 Sheets-Sheet 2 Filed April 30. 1947 FIG.7.

ATTORNEY.

Patented Sept. 29, 1953 ELECTRON swrrcn CONTROL SYSTEM Trevor H. Clark, Boonton, N. J assignor to International Standard Electric Corporation, New York, N. Y., a corporation of Delaware Application April 30, 1947, Serial No. 745,013 In France April 7, 1939 Section 1, Public Law 690, August 8, 1946 Patent expires April 7, 1959 9 Claims. 1

The present invention relates to control systems actuated by electricalimpulses and particularly to control circuits which follow the impulses received and do not operate when no impulse is received.

The invention more particularly relates to control systems of this type adapted to control cathode ray switches in electrical transmission systerns such as automatic telephone systems.

It is an object of this invention to provide circuits for the control by impulses of electronic switches which actuate said switches so as to displace an electron beam thereof from one positicn to another, corresponding to different numbers of incoming impulses.

Another object of this invention is to provide circuits which control an electronic switch by impulses, by transforming groups of incomingimpulses into pairs of direct potentials for the deflection or deviation of the electron beam of the switch so that each pair of potentials has a combination of values corresponding to the number of impulses in the incoming group.

In accordance with one of the characteristics of the invention the control circuit, for deviation in one direction of the beam of an electronic switch under the action of incoming impulses, contains, in shunt across the terminals of a condenser, a gas discharge device (having either a hot or a cold cathode) in series with the magnet of a relay, the said device by its ionization, due to an accumulated charge in the condenser under the action of a predetermined number of received impulses, acting to discharge the condenser and to actuate said relay in order to conrol devia ons of e am n a s c d r tion.

A control circuit of an electronic switch according to the invention may comprise a first control circuit provided with a capacity in shunt with a gas discharge device in series with a relay, this capacity accumulates a charge accord ing to the number oi incoming impulses by partially discharging for each impulse another capacity, normally in closed circuit on a source of direct potential, 1., e., in closed circuit thereon between impulses, which, on each impulse, gives up, charge to the first capacity and to a first deflector unit of said electronic switch. When a predetermined number of impulses has; been received, the potential on the terminals of the first condenser reaches such a value that it involves the discharge of said discharge device and consequently the momentary energization of therelayin series therewith. This. relay: actuates a second control circuit of the electronic switch which circuit, by a similar arrangement of capacities and a fixed source of potential, applies, every time a predetermined number of impulses has been received, an incremental charge on a second deflector unit ofsaid electronic switch, the second deflector unit acting to produce beam deviations in a difierent direction than that of the deflections causedby the first one.

In another embodiment of this invention a relay which couples the two control circuits comprises a first winding which, in a series circuit with the discharge device, is in shunt across the terminals of the storing condenser, and a second winding passing through an armature and a contact also in shunt across this condenser.

In still another embodiment'the said coupling relay is provided, in addition to its set of contacts, which actuate the second control circuit, with a set of contacts for energizing another relay which closes an auxiliary discharge circuit of the condenser through, a, resistor in response to each energization of the coupling relay and thus accelerates the completion of the discharge of the condenser.

The invention will be described in particular with respect. to. an impulse transmitting system comprising a telephone dial which controls the position of the electron beam of a cathode ray marker switch. However, it is clear that the in vention can equally well be. applied to a similar control function in other systems such as metering systems of any kind, devices for counting objects, for counting revolutions, etc, in which the speed of metering is only limited by the speed of operation of relaysv employed in the control circuits and/or the period of discharge of any gas discharge device therein.

In the embodiment to be described the electronic switch has its beam deflect-ed in two directions at right angles to each other. However, it is obvious that the invention may be adapted to an electronic switch with other and/or more complex beam-position patterns. successively actuated control circuits are employed each of which, with the exception of the last one, comprise in addition to a stepping condenser a gas discharge device in series with a relay winding both on the terminals thereof-the relay serving to couple any of the control circuits to the next one.

In particular the invention will be described in detail in connection with the attached drawings in which Fig. 1 represents one embodiment of the invention.

Fig- 2: shows one type of po ition patt rn in which collecting electrodes (terminals) of the cathode ray switch may be arranged.

Figs. 3 and 4 show curves used hereinafter to assist in the description.

igs. 5, 6 and 7 show three possible modifications of the circuit of Fig. 1.

In Fig. 1 when impulses emitted from an ordinary telephone dial I, are received by a relay 2, its armature 3 follows the impulses transmitted and actuates a control circuit for a cathode ray switch 4. The circuit of relay 2 passes from a grounded battery 5 through a winding of the relay, through one wire of line circuit 6 through contacts (not shown) of dial I, through the other line wire, and through a second winding of relay 2 to ground.

Armature 3 of this line relay 2, normally (when it is not receiving an impulse) rests on its back contact, thus closing a circuit for charging a condenser I from a battery 8 or some other source of direct potential. The front contact of armature 3 is connected to a terminal 9 of the first control circuit of electronic switch 4. A point of fixed connection between condenser 1 and battery 8 is connected to the other terminal I of the control circuit. Electronic switch 4 is represented for the sake of simplicity by two pairs of deflection plates, II and I2. However, it is obvious that in other embodiments of this invention other deflecting means such as magnets may be employed. Likewise while this device may be an ordinary cathode ray tube with its fluorescent screen replaced by a set of conductive terminals or contact studs (such as indicated in Fig. 2) it may likewise be a cathode ray switch of any suitable form, such as one of the devices described in the French Patent #857,575 published September 19, 1940.

The positioning control circuit of electronic switch 4 comprises a first control circuit formed by a condenser I3 in shunt between terminals 9 and I0 and a series circuit including a gas discharge device I4 and the winding of a relay I5 connected across the terminals of said condenser I3. This first control circuit is connected to a pair of deflection plates II of switch 4. Bias source I6, shown in Fig. 1 as a battery, is connected between the control grid and the oathode of discharge device I4 in order to determine its firing potential. Device I4 does not necessarily have to consist of a gas triode tube. It may consist of any device which breaks down to have very low internal resistance under a predetermined electrical tension but has very high resistance when the value of the potential across its terminals is too low either to sustain a breakdown which has been established or to establish a breakdown. The deionization time of device I4 should be low with respect to the period between two successive impulses sent from dial I.

Relay l5 serves as a coupling between the first control circuit and a second control circuit which comprises a condenser I1 normally in closed circuit with a battery I8 through an armature I9 (and its back contact) of a relay I5. A stepping condenser 20, whose function is similar to that of condenser I3 of the first control circuit, is connected between the front contact of armature I 9 and a fixed connection between battery I8 and condenser II. Condenser 20 is permanently connected across the second pair of connecting plates I2 of cathode ray switch 4.

The operation of a circuit of this kind is as follows:

When dial l is operated to send impulses over line 6, relay 2 follows these impulses as its energizing circuit is intermittenly closed by the contacts (not shown) of dial I.

As mentioned above, when the dial contacts are open and relay 2 is inoperative, armature 3 rests on its back contact. Under these conditions condenser I is in a closed circuit with battery 8 and quickly charges to the potential thereof since the effective resistance of the charging circuit is very low. Each time the dial contacts are closed relay 2 is actuated and armature 3 swings to its front contact disconnecting condenser I from battery 8 and completing its connection across condenser l3-more specifically with respect to Fig. 1-it completes the connection of condenser 1 across terminals 9 and III.

The potential on the terminals of condenser 1 is thus applied to the terminals of condenser I3 as well as to the main gap of gas discharge device I4 through the magnet of relay I5. The potential on the terminals of condenser I is also applied to the part of deflecting plates II of switch 4. The electron beam of switch 4 will be deflected and when current has ceased to flow from condenser 1 into condenser I3 the beam will have moved from its rest position (if the received impuse is the first one), or from a position in one of the horizontal rows shown in Fig. 2, to a new horizontal level, i. e., a position in the first or next higher horizontal row. For example, assuming that the impulse received is the first one of a group (or that the group consists of only one impulse, i. e., the digit transmitted is 1) the beam will move from some suitable rest position in or opposite to an end of the left vertical column of positions shown in Fig. 2, from some rest position, which perhaps is entirely oiT the screen, up to the level of the bottom horizontal row. Thus it will move from a non-working position to the first position representing a digit. On account of the choice of relative values of capacitance of condensers I and. I3 and of the bias of the discharge device, the potential across condenser I3 acquired by a r single charge being receivedv in condenser 1 will not be of sufficient magnitude to cause the ionization of device I4 and the consequent operation of relay I5. Since the resistance of the discharge device therefore remains very high, condenser I3 cannot discharge but, instead, will store the first charge.

At the end of the first impulse relay 2 will be deenergized and armature 3 will return to its rest contact, thus again closing the charging circuit of condenser I from battery 8. Condenser I will be recharged practically instantaneously to the full potential of battery 8 for reasons already stated. However, for the time being, the electronic beam of switch 4 will remain on position 1 since the potential which maintains it there will continue to be applied only by condenser I3.

When a second impulse is thereafter transmitted from dial I relay 2 will again be actuated. Armature 3 will again swing from its rest contact to its front contact opening the circuit of battery 8 with condenser I and connecting together condensers I and I3. Condenser I3 will receive an additional charge and its new potential will be substantially equal to twice that produced by the first charge. The electron beam will be deflected vertically to position 2 under the action of this increased potential. However, the bias applied to device I4 is so chosen that even after condenser I3 has received this scribed above. condenser I will be; recharg d: su

stantiall-yinstantaneously. The electronbeam will remain on position 2.

Upon. the reception. of the third. impulse: th

operation, of: the firstv control. circuitwill. be Sinai-- ar' to.- thatalready described with respect: to the.- first. two; impulses. and the beam; will. reach toppositi'cn. a or the left. vertical: column of Fig.- 2' At; the; end. or this impulse'eond nser 1 will. again quickly be recharged.

The de iption thus far has: concerned only the first control; circuit, e.,, that. which ap lies; vertical; deflection po ntialstolements: ll of switch 4.v According: to the embodiment of,v switch 4. shown in Fig. Zrthe next. position. which the. beam is to take: will be: that. num eredh t. the; lowest position of the second. vertical; column, Therefore it is. necessary to. provide on the fourth; impulse an actuation. of; the. second control circuit, i. e.., the.- application; of. a hori; zontal deflecting:v potential to elementsll f switch. 4* and at the.- same time actuation of the fi-rst,cntro1.-, circuit to cause, it. to restore, the. beam; to the low level. of the first horizontal row. For this: purpose the.- bias on discharge device M is; adjusted so that. it, willbe ionized (and rendered conductive) by the potential attained across condenser [3. on, its receiving a. fourthcharge; in response to the fourth. impulse. Ac..- cordingly, when the fourth impulse. is, received and relay 2 operates in the manner already dc,-w seribed, the. total charge accumulated in condenser t3- wi-llbelarge enough, so that. he. result,- ing; potential across. its: terminal will onize he discharge device, breakin it down-and l-educing its internal impedance. Condenser 13' will. dis charge through this low impedance and the. winding or relay I5 and the potential-across it terminals will. drop down near the. extinction, otential of the. gas discharge derid Two su stantially simultaneous enacts-on switch wi a result therefrom i The first client. will be the cancellation oi most of the deflection potential applied betwee 1 33 merits H oi the switch This will result.- b-i-"in-sine thebeam down to the level of the. bo *tom row of numbered positions- At same time a'po tential will be applied.- thro h the second; control circuit, to deflection plates 12... This otential will have-such a valueas to. laterally displ'aceth-e electron beam from the first column or the numbered positions to-the. second one,

Therefore,- the electron beam will come. to re t,

on the position marked 4'in Fig... 2.

It is obvious that after a, complete cycle: of; operation of a system including switch 4 tier example, in a telecommunication sys m em.-

ploy-mg the present invention, after a call has been put through and has ended), associated switching means (not shown) will: be needed restore the control circuits to normal by ful y discharging condensers l3 and 0. permit the electron beam under the control of static pQSi-i tioning otentials, to swing back to a non-working rest osition, for exampl a. posi on whi h is opposite the bottom. end of th e t ve t column, and below 'the level of the bottom horizontal, perhaps completely off, screen.

However, it is also obvious that in other embodiments of this invention static positioning potentials may so be applied to elements H and meats a, gas disc teral. d fle tion f the gain op rate and the eomw-ili hail; the l ft; ver c l c l mn; and the:

bottom hor zon al row. ic he ar a now denated as 1-. Big: .2). when con nser 3 and .0. are full disc ar e I uch embodi xtinction; potent al; mar e m yed Such a dev ce, when t ti es. will comp e y i c ar e ondenser I 3. and the.- eam w ll f ll ba ub? stantially t the; level or. the bott m h r z n al row of n m ere p sition Of. c rse, n. ch n r an ement the p s tion now sh wn as 1.. in a wool be an idle osition, .e.- it wou d terminal would be unused. In such an embodi merit the. useful po i n. that; or spondin o ahrstreceir d imouls i. w uld: e at the peel t onnovc desi nated. as 2. on. Fist. 2.:

The second contro circuit operat s to displace the ectron. beam" l t ra ly f m. one verti-v al. column of. n s ons to th next as f llows: when dischar de ic 4 b comes conductiv condenser i3. is: di char e hrou h it. and: the

maset of relay t. Relay 5 h refore i en r iz d. for a. sh rt time h ischarge time). It will turret-ion with reshect t the second cone. ol. ircuit: ina manner which corresponds; to the function of relay 2; wi h respect. o h first control circuit- R lay 2 repeats e ch. re eived mpulse, relay l e ts nly predetermined ones of the received. impuls s- In. some embodiments. these may e every thir or iourth. or nth received mpu se- Armature- IQ of relay is swings. from its ack. contact; to its front: ontac openin h ircuitior chargin condenser H; from; battery 1:8 and; connec ing con enser 11 para l wi h teppin con ens r 20. The char received on h steppin condenser is anpliedacross another pair of deflecting plates of switch 4 which cause beam. In. order that h deflec i n. for one char e. (one step). will be the distanc betweentwo,verticalcolumns ofpo ie tions. shown F st 2,. the values of condensers I1, and 3 11 as well as that of; battery l8. must be pronerlr selected.

Condenser 20 of the second control circuit will tore t fi st chaise until the nest. operation. of ayi. thatis thesevehth. impulse is. re-.

ceived from dial L At this. seventh. impulse. re-.

bla nedend ondenser 2.41 will. ec iv a addi-- tional charge from condenser ll whereby the. eam. will be deflec ed; o he th d-- lumn- In the same way on the tenth impulse relay [5 will beam will be further deflected to the fourth column.

Q YIiQQ-SIL a ter this apparatus has translated the transmission of a group of impulses from dial I in o 8' Positional representation of the number o impulses in the. roan, and. after it hassitored he representation until; u l us as b mad or; it, means will be required to restore the ape aretus tol s eady condi ion. tor its next. usefulcrc eof oo a'tlon,

aux iar. e c. it ill e required.- A. tele communication ystem, for exam le ch w d include subscribers stati ns exchang s etc. a d which would. include alsov apparatus-a co din to this invention, could b arran ed in accordance th we known au omatic t lep o e art so that the sys em w u d com s eans f r leasin switch 4 and restoring it to a ready condition after each occasion where use has been made, of information stored in it, i, e. after each complete cyc-leof its operation.

o device, having a ery l ither-entirelr lack ac nduct ve te minal or ts v l e Such an auxiliary circuit may comprise metallic short circuits, such as could be provided via relay armatures to be placed in shunt across stepping condensers l3 and 20 after switch 4 has completed one operating cycle. This would cause the beam. to swing to its rest position from its last used operating position. That is to say relay means could be employed to discharge condensers l3 and 20, in order to permit the electron beam to swing back both laterally and vertically to a rest position opposite the lower end of the first vertical column and either at or below the level of the bottom horizontal row (depending upon embodiment, i. e., where the first used position is located) It might be desired to embody the invention in apparatus for counting long trains of pulses by translating the number thereof into a multidigit representation in which each of a plurality of cathode ray switches is assigned to represent a different digit for example, the thousands digit, or the hundreds digit, or the tens digit or units. In such an embodiment the number of positions on each switch would be selected in accordance with the numerical system used. Ten position switches would be best for a. decimal system. In such a device upon the receipt of impulse number 11 the beam of the tube adapted to represent unit digits should be made to swing to its rest or 0, position and that of the tens digits tube should be made to swing to its position number 1. In such a device the second control circuit could be made to include a discharge device such as device l4 shown for the first control circuit and in such an arrangement both discharge devices would operate on the th impulse. A suitable position-pattern on the target area would be one containing 9 positions in three rows and three columns.

The individual and relative values of the condensers 1 and I3 and I! and 20 as well as of other circuit elements can be suitably chosen in accordance with design practices well known in the art. In deciding on the proper values the following factors may be taken into consideration.

1. The magnitude of current which may pass through the contacts of relays 2 and I5, respectively without damaging them.

2. The speed of discharging (or charging) of condenser [3 by deflection plates II or of condenser 20 by deflection plates [2.

3. The values of the direct potentials supplied by sources 8 and I8.

4. The deflection potentials required by the cathode ray switch.

5. The characteristics of the gas discharge device.

6. The desired amount of deflection, i. e., the spacings of the numbered positions or terminals.

It is possible to obtain useful information from curves such as those of Figs. 3 and 4, as to the effect of the capacitance values of I and I3 (or H and 20) having different ratios. In Fig. 3 variations of the accumulated potential, E, across condenser [3 are plotted against the number of impulses received for 8 different values of the ratio, N, of the capacitance of condenser I3 to that of condenser I. The values of potential, E, are also shown expressed as fractions of the potential, e, which is the direct potential supplied by battery 8. The respective values of N used in plotting the different curves are indicated on the drawing for the individual plotted curves.

In Fig. 4 different values of the ratio between increments in potential across condenser effected by a first impulse and a fourth impulse are plotted against different values of the ratio, N, of the capacitance of condenser l3 to that of condenser I. It is seen from this curve that when the ratio N is as large as '7 the first contribution of potential is only 1.5 times as great as the fourth contribution, i. e., increment. However, when N equals 1 (when the 2 condensers are of equal capacity) the first contribution or increment is 7.5 times as great as the fourth.

If the capacity of condenser 1 be great with respect to that of condenser I3 successive contributions of potential to condenser 13 from condenser will be markedly smaller progressively, i. e., the rate of change of potential plotted against the number of impulses received will not be linear. This is clearly shown by the curves of Fig. 3 and is implicit in the curve of Fig. 4.

If the capacity of condenser I is too small with respect to that of condenser l3 the potential of battery 8 will have to be very great in order to obtain significant increments of charge for condenser |3 from condenser 1, each time an impulse is received. In the same way when the capacity of condenser I1 is low with respect to that of condenser 20 it becomes necessary for the potential of battery II! to be very great.

If both of the condensers are selected with very high values of capacitance, the current between them, which has to pass through the armature and front contact of relay 2, may be great enough so that the points will stick. Obviously this must be avoided.

If condenser I3 is of too low a value it will be discharged (or charged) by deflection plates II. This also is to be avoided and, for the same reason, the value of condenser 20 must be sufflciently large with respect to the capacitors between deflection plates l2.

The use of a system of this kind permits greater dial speed than is possible in systems with all-mechanical metering of the impulses.

It is obvious that electronic switches, according to this invention, may have different numbers of positions than 12. The particular switch shown herein was chosen only by way of example. For a telephone system based on the decimal numerical system a ten position circuit would probably be best.

On the other hand it is obvious that the target area could be conveniently sub-divided to include a great many commutator terminal areas, or if it is desired to base a telecommunication system on a numerical system whose base number is much higher than 10 so as to reduce the number of separate digits dialed. In fact. a single cathode ray switch according to the present invention which has a sufficiently large number of terminals could be employed to count impulses up to a fairly large number and to record the count it makes.

The circuit shown in Fig. 1 is obviously capable of numerous modifications and adapations without departing from the scope of the invention. By way of example, Figs. 5, 6 and '7 show three possible modifications thereof. Figs. 5-7 show principally only the modified portions. It should be understood that any one of these portions can be fitted into Fig. 1 to replace the corresponding portion thereof, which is shown to the right of terminals 9 and 10 in Fig. 1. In these Figs. 5-7 elements which are similar to those of Fig. 1 are given the same reference numerals. complete operation of the modified systems of -7 will not be described in detail since it is similar to that already explained for Fig.1. The operation of modified portions will, however, be described.

Referring first of all to Fig. 5, "the modification incorporated in this embodiment comprises the provision in coupling relay of an additional winding 22. The first winding, now'bearing reference numeral 2| in this'figure, is still connected across condenser 13 in series with discharge device M. The extra winding 22 is connectable across this same condenser by an additional armature 23, of this relay l5, .and its cooperating front contact. In this way every time that gas discharge device l4 fires, energized throughits winding 21 and later, when its armatures have made their front contacts, armature 23 closes the energizing circuit of awe iliary winding 22. This will render the discharge of condenser l3 somewhat more rapid and at the same time will assist relay 1 5 to actuate its armatures in a very positive manner until condenser I3 is substantially fully discharged. The provision of the winding 220f relay 15 may not be necessary. Instead, armature '23 and its contact may be adapted to short circuit condenser i3 directly, i. e., without conducting through an-additi'onal winding the current which they divert. In such a case this modification would serve only to shorten the condenser-discharge time. In this case :it will be necessary to provide, as already explained, a static deflecting potential to "hold the beam on a level with the lowest row of positions.

The modified circuit of Fig. -6, in addition to circuit elements of Fig. 1, comprises a second armature 24 for relay I5. This armature makes its front contact when relay I5 is actuated and energizes a second relay 25 via a "circuit containing battery relay 25 may, of course, have a very fast and positive action. It is provided with an armature 21, which on making its operating contact, cannects 'a low resistance 28 "directly across "condenser l3. Because of the 25 and the low value of the resistance, condenser l3 will complete its discharge rapidly after "the initial actuation of relay l'5. It will complete its discharge both through the resistance 28 and the parallel-series circuit of the magnet "of relay I 5 and discharge device I4. By'this arrangement the discharge of condenser l3 cannot be excessively prolonged as it "would be for example if the resistance of the magnet of relay 15 were very high. will have ample time to perform its function of impulsing the second control circuit.

In Fig. -7 triode gas discharge device I4 is replaced by a cold cathode tube 29. This tube can either have two electrodes or, asis shown, 'ltmay have three. In the latter :case the :discharge is produced between the electrodes 30. Thereafter a third electrode 3| will maintain ionization of the tube until condenser [3 has been discharged to a-desired low residual potential. At 32 isr-indicated .a resistor connected between this third electrode and the positive terminal of a source of .direct potential. The negative terminal of the .source .is connected to another electrode of tube 29, viz., one of the electrodes numbered 30.

The value of the potential applied to this electrode and the value of this resistor are selected to insure correct operation of the circuit in the relay is initially '26 for energizing it. This second positive action'of relay.

At the same time, however, relay Hi 1 manner indicated. Oth'er modifications "and adaptations may also employed without departing from the scope of the invention.

What' is claimed is:

'1. Apparatus for'receiving a group-of impulses and actuating 'a cathode ray switch in accordance with the number of impulses in the group, comprising a first control circuit including a first stepping condenser for receiving the group of impulses and translating the reception of successive impulses thereof into successive incremental chargings :of "said first stepping condenser, a cathode may switch including a target area, electron gun means for "projecting a beam of electrons onto the area, first deflection electrodes for defiect'ingthebeam to move its projection on the area in a first direction and second deflection electrodes for deflecting the beam to move its projeetionon "the area in a second direotion, means cfor applying any potential accu mulated across the first stepping condenser to the first :deiiection electrodes to control the amount oi'the movement of the projection in the first direction inaccordance with said number,

a second control circuit including a second stepping condenser connected to the first control circult to respond to selected ones of successive impulses to translate them into successive in cremental chargings of said second stepping condenser, means for applying any potential accumulated across the seoond'stepping condenser to the second deflection electrodes '-to "control the amount "of the movement oi'the projection the second direction in accordance with said number, the directions and 'amounts of the movements being coordinated so that the projection will be moved to a position on the area correspending in *a predetermined manner to said number.

2. Apparatus as in-claim l in which the switch includes a plurality of terminal studs each having a predetermined position on the target area which corresponds to a number, the positions being so arranged that a group "of impulses is received said projection will be moved onto the stud whose position corresponds to the same number as "the number of impulses in the group.

3. Impulse receiving apparatus for translating the number of "impulses in a group of received impulses into a stored representation thereof, comprising a source of impulses, .a cathode my device having a target area, an *electron'gun for producing --a *beam "of electrons and projecting it on the area, 'and beam deflecting means, -a first control circuit connected to the source and to the beam deflecting means and responsive to a group of impulses received therefrom to deflect the beam in one -"direction over the area for a predetermined distance in accordance with the number of the impulses in the group, 'a second control circuit connected to the first control *cirthe area, the .location of each position proportional "to a given nuniber of impulses in a received group. p

4. Impulse receiving apparatus as in claim 3 in which each of the selected ones of the imthe-beamto move pulses is separated from the next selected one by an equal number of impulses.

5. Apparatus for receiving a group of impulses and for producing and storing a representation of the number of impulses in the group comprising an impulse receiving circuit, a cathode ray device having two co-ordinate deflecting circuits, means for translating a predetermined succession of said impulses into a first deflecting voltage, means for applying said first deflecting voltage to one of said deflecting circuits, means included in said first translating means for translating individual impulses within said predetermined succession of impulses into a second deflecting voltage, and means for applying said second deflecting voltage to the other of said deflecting circuits.

6. Apparatus, as defined in claim 5, in which the means for translating a predetermined succession of impulses into the first deflecting voltage comprises a trigger device set to operate at a predetermined voltage, means for applying the second deflecting voltage across said device, whereby said device will trigger when said second deflecting voltage equals said predetermined voltage, and means controlled by the triggering of said device for producing the first deflection voltage.

7. Apparatus, as defined in claim 6, in which each of the translating means comprises a condenser and means for intermittently charging said condenser with predetermined equal charges.

8. Apparatus for receiving impulses, for translating the number of impulses into a representation thereof, and for storing said representation, comprising a source of impulses, a first control circuit comprising an impulse receiving and repeating device connected to said source of impulses, a first storage condenser, a first source of direct potential, the condenser being connected to the source of potential by the repeating device between impulses to be charged from said source, a first stepping condenser which is connected to said storage condenser by said repeating device upon the receipt of an impulse to receive charge therefrom, a cathode ray device including a target area, an electron gun for producing a beam of electrons and projecting it on said area, and beam deflecting means connected to the stepping condenser for deflecting the beam to move its projection successively in a predetermined direction on said area as successive impulses are received and to position it on a subdivision of the area corresponding to the number of received impulses, a relay, a gas discharge device connected across said stepping condenser through said relay, adjusted to ionize so as to discharge said stepping condenser after said stepping condenser has received enough charges for a predetermined potential to be accumulated across its terminals, said relay being momentarily energized by the discharge to repeat predetermined ones of the impulses and to produce for each one thereof a local impulse, a second control circuit comprising said relay, a second source of direct potential, a second storage condenser which is connected to said second source of potential by said relay between local impulses to be charged therefrom, and a second stepping condenser which is connected by said relay each time it repeats an impulse to said second storage condenser to resaid discharge device being ceive charge therefrom, said second stepping condenser being connected to said deflecting means for deflecting said beam to move its projection on said area in a second predetermined direction which is coordinate with said first direction, the resultant deflections cooperating to position said beam projection on a subdivision of said area corresponding to the number of received'impulses.

9. Apparatus for receiving impulses, for translating the number of impulses into a representation thereof, and for storing said representation, comprising a source of impulses, a first control circuit comprising an impulse receiving and repeating device connected to said source of impulses, a first storage condenser, a first source of direct potential, said condenser being connected to said source of potential by said repeating device between impulses to be charged from said source, a first stepping condenser which is connected to said storage condenser by said repeating device upon the receipt of an impulse to receive charge therefrom, a cathode ray device including a target area, an electron gun for producing a beam of electrons and projecting it on said area, and beam deflecting means connected to said stepping condenser for deflecting said beam to move its projection successively in a predetermined direction on said area as successive impulses are received and to position said beam on a subdivision of said area corresponding to the number of received impulses, a relay, a gas discharge device connected across said stepping condenser through said relay, said discharge device being adjusted to ionize so as to discharge said stepping condenser after said stepping condenser has received enough charges for a predetermined potential to be accumulated across its terminals, said relay being momentarily energized by the discharge to repeat predetermined ones of the impulses and to produce for each one thereof a local impulse, a second control circuit comprising said relay, a second source of direct potential, a second storage condenser which is connected to said second source of potential by said relay between local impulses to be charged therefrom, a second stepping condenser which is connected by the relay each time it repeats an impulse to said second storage condenser to receive charge therefrom, said second stepping condenser being connected to said deflecting means for deflecting said beam to move its projection on the area in a second predetermined direction which is coordinate with said first direction, the resulting deflections cooperating to position the projection of said beam on a subdivision of the area corresponding to the number of received impulses, and means which are responsive to each energization of said relay to accelerate dischargings of said first stepping condenser.

TREVOR H. CLARK.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,122,102 Lundell June 28, 1938 2,132,655 Smith Oct. 11, 1938 2,221,452 Lewis Nov. 12, 1940 2,224,677 Hanscom Dec. 10, 1940 2,267,827 Hubbard Dec. 30, 1941 2,404,106 Snyder July 16, 1946 2,435,840 Morton Feb. 10. 1948 

